Most portable electronic devices such as laptop and notebook computers, mobile phones, and game devices have flat viewing screens unlike the cathode-ray-tube (CRT) monitors of conventional desktop computers. Nevertheless, users still generally expect the flat viewing screens to provide performance equal to that of CRT monitors. To meet this demand, computer manufacturers have sought to build flat panel displays (FPDs) offering superior resolution, color, and contrast, while at the same time requiring minimal power consumption. Liquid crystal displays (LCDs) are one type of FPD that satisfy these expectations. However, the liquid crystals of an LCD are not self-luminescent. Rather, the LCD generally needs a surface emitting device such as a backlight module which offers sufficient luminance (brightness) in a wide variety of ambient light environments.
FIG. 7 is an exploded, isometric view of a conventional backlight module, and FIG. 8 is an assembled view of the backlight module shown in FIG. 7. The backlight module 1 includes a light guide plate 11 and a light source 13. The light guide plate 11 includes a light output surface 112, a bottom surface 113 opposite to the light output surface 112, and two adjacent light incident surfaces 111 interconnecting the light output surface 112 and the bottom surface 113. The light source 13 includes an L-shaped lamp 131 and two electrode cases 133. The electrode cases 133 are respectively connected with two ends of the lamp 131. The lamp 131 is disposed adjacent to light incident surfaces 111. A plurality of rubber rings 15 is engaged around the lamp 131, so as to prevent the lamp 131 from contacting the light incident surfaces 111.
However, the light source 11 and the light guide plate 13 are generally not firmly fixed to each other. During transportation of an LCD incorporating the backlight module 1, the LCD is liable to sustain vibration or shock, and the lamp 131 may be damaged or broken. In addition, in assembly of the backlight module 1, the rubber rings 15 have to be attached on the lamp 131 before the light source 11 is attached to the light guide plate 13. This is an unduly laborious process, which increases the time needed for assembly and thus adds to manufacturing costs.
Therefore, what is needed is a backlight module which can overcome the above-described problems.